1. Field of the Invention
This invention relates to tape transport systems and, more particularly, to tape threading mechanisms utilized to feed tape along a path between tape supply and take-up reels in a tape transport mechanism.
2. Related Art
Off-Line Data Storage Development
In the course of developing various systems for the storage of data on magnetic recording tape, particularly for high volume data storage devices, a variety of different formats have been developed. Many of these formats call for the tape to be contained in an appropriate cartridge, both to facilitate handling of the tape while in use, and to protect the tape while in storage.
To this end, the IBM Corporation has developed a tape cartridge which is primarily intended for use in its Model 3480 data storage system for the storage of relatively large quantities of data (on the order of 200 megabytes). Details regarding the construction of this type of tape cartridge (hereinafter referred to as a 3480-type cartridge) may be found in U.S. Pat. No. 4,452,406.
By way of general description, the 3480 tape cartridge is a single reel cartridge with a length of 1/2 inch wide magnetic tape stored in it. The cartridge housing protects the tape from damage while allowing the tape reel to be driven from a drive mechanism on the underside of the cartridge housing. The tape is withdrawn from an opening formed at one corner of the cartridge. A leader block attached to a free end of the tape allows the tape to be withdrawn from the cartridge for read/write operations.
The 3480 tape cartridge has found wide acceptance in the data storage industry for a variety of reasons. One important reason for this is that, unlike other types of tape cartridges and cassetes which have been developed for use in the off-line storage of data, the 3480 tape cartridge houses only a single reel of magnetic recording tape in a relatively small, space-efficient package. The resulting package is therefore conveniently stored and easily used.